Conventionally, a light emitting apparatus employing a ceramic substrate, a light emitting apparatus having an organic resist layer as an insulating layer on a metal substrate, and the like are known as a light emitting apparatus including a light emitting element which is provided on a substrate.
Patent Literature 1 discloses a technique to form a laminated plate having a tracking resistance by (i) forming a ceramic layer by thermally spraying ceramic on one surface of a copper foil, (ii) applying an adhesive to the ceramic layer, and (iii) stacking a coated fabric, which is made by impregnating a paper base with phenolic resin, on the adhesive-applied surface.
Further, Patent Literature 2 discloses a thermoelectric conversion apparatus employing a metal substrate on which an insulating film layer made of a ceramic paint is formed.
Furthermore, Patent Literature 3 discloses a technique to form an insulating film by applying a ceramic paint to a base such as an aluminum plate.